Posts

Enhanced Perceptual Rub & Buzz Measurement for Testing Automotive Loudspeakers

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Loudspeaker Rub & Buzz faults are a problem for automotive manufacturers as they sound harsh and immediately give the perception of poor quality. There are two places such faults can occur – during speaker manufacturing and installation of the speaker in the car. A buzzing loudspeaker in a car is disappointing to a customer and is costly to replace. It is also challenging for a service center to determine exactly where the buzzing is coming from and whether it is caused by a faulty loudspeaker or bad installation. Perceptual distortion measurements are often considered the holy grail of end-of-line testing because rejecting speakers with only audible faults increases yield. Although such measurements have been around since 2011, production line adoption has been slow because until now, sensitivity to background noise has made limit-setting challenging. In this paper, a new algorithm is introduced that uses advanced technology to reduce the impact of background noise on the measurement and offer more repeatable results. This facilitates limit setting on the production line and makes it a truly viable production line metric for increasing yield. This same metric may also be used for end-of-line automotive quality control tests. Results from various algorithms will be shown, and their correlation to subjective and other non-perceptual distortion metrics explained.

Authors: Steve Temme, Listen, Inc.
Presented at 2022 AES Automotive Conference, Dearborn, MI

Full Paper

End of Line Distortion Measurements

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Steve Temme discusses the importance of detecting manufacturing-induced defects such as Rub & Buzz and Loose Particles during end-of-line testing, and explains the various algorithms that are used. He compares conventional and perceptual metrics for the measurement of Rub & Buzz, including Listen’s new enhanced Perceptual Rub & Buzz algorithm, and discusses why it can be beneficial to use both conventional and perceptual measurements in tandem.

Full Article

Production Testing Seminar

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March 10th, 2022. 9.00am and 2.00pm Eastern US time (6.00am and 11.00am West Coast time)

In this short seminar, Les Quindipan explores the use of SoundCheck for end-of-line production testing. He discusses typical test configurations and the type of measurements that can be made, how to set pass/fail limits and how to optimize tests for high throughput.

He will also explain how SoundCheck is easily scaled for high volume production testing, with such features as external control via another program and auto-saving data to databases, and how SoundCheck’s capabilities are easily expanded through the use of custom steps to control all types of devices and test fixtures.

This seminar will be of interest to anyone considering a production line implementation of SoundCheck, or curious as to how to transition R&D measurements to fast and effective end-of-line test.

This event has passed. Watch the recording.

Basic Loudspeaker Measurement Seminar (China) / 扬声器测试基础篇

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Oct 13th, 2021. 10.00am China Time / 2021 年 10 月 13 日上午 10 点（中国时间）

Join Les Quindipan and Anastassia Tolpygo on Oct 13th for a seminar on basic loudspeaker testing. This introductory seminar is aimed at anyone new to audio measurement, specifically loudspeaker testing. It will begin with an introduction to the basic design of a loudspeaker, including how a typical loudspeaker works. Various loudspeaker measurements will be explained, such as frequency response, distortion, sensitivity, phase/polarity and impedance, and how they might offer indications as to potential defects in a speaker. Typical test configurations for both R&D and end-of-line production test will be shown. A complete speaker test will be demonstrated, using SoundCheck and our free Loudspeaker complete test sequence. This will include setting up software and hardware, calibrating and configuring the test (e.g. setting pass/fail limits) and a discussion of the results. There is no charge for this seminar, but registration is required.

于10 月 13 日加入Les Quindipan 和 Anastassia Tolpygo主持的有关基础扬声器测试的研讨会吧。

此研讨会目的是向任何不熟悉音频测量的人介绍一下音频测量, 特别是扬声器测试。在研讨会中,首先会介绍扬声器的基本设计, 包括典型扬声器的工作原理。并将解释各种扬声器测量，例如频率响应、失真、灵敏度、相位/极性和阻抗, 以及扬声器测试如何提供有关扬声器潜在缺陷的指示。研讨会将展示用于研发和下线生产测试的典型测试配置。

在研讨会中将演示完整的扬声器测试。使用 SoundCheck 和我们免费的扬声器完整测试程序。这将包括设置软件和硬件、校准和配置测试（例如设置通过/失败限制）以及对结果的讨论。本次研讨会不收取任何费用，但需要预先报名。

This event has already taken place. Check out our Youtube Channel for the recording.

 

Evaluation of audio test methods and measurements for end-of-line loudspeaker quality control

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In order to minimize costly warranty repairs, loudspeaker OEMS impose tight specifications and a “total quality” requirement on their part suppliers. At the same time, they also require low prices. This makes it important for driver manufacturers and contract manufacturers to work with their OEM customers to define reasonable specifications and tolerances. They must understand both how the loudspeaker OEMS are testing as part of their incoming QC and also how to implement their own end-of-line measurements to ensure correlation between the two.

Authors: Steve Temme, Listen, Inc. and Viktor Dobos, Harman/Becker Automotive Systems Kft.
Presented at ISEAT 2017, Shenzhen, China

Full Paper

In-Vehicle Distortion Measurement

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Authors: Zarina Bhimani, Steve F. Temme (Listen, Inc.), Patrick Dennis (Nissan Motor Co.).  Reprinted from the 2017 Loudspeaker Industry Sourcebook.

Steve Temme and Patrick Dennis discuss their research exploring test methods that will help determine audible distortion and enable manufacturers to test sound equipment after it is installed

Full Article

 

 

New Speaker Testing Brochure

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lisBrochureSpeakers.inddA new 4 page brochure outlines Listen’s capabilities in loudspeaker and  microspeaker testing. SoundCheck offers simple, fast and accurate testing of any loudspeaker – no matter what the form  factor, functionality, connector or additional features. It measures a full range of driver parameters via traditional analog or digital, wireless/Bluetooth, Toslink, HDMI or USB connections, as well as microphone performance, surround sound and more.
Measurements that SoundCheck can make include:

  • Frequency response
  • Phase & polarity
  • Distortion: harmonic, IM, multitone & non-coherent
  • Rub & Buzz (inc. Perceptual Rub & Buzz)
  • Impedance
  • Directivity (including polar plots)
  • Max SPL
  • Power rating tests
  • Simulated free field measurements
  • Thiele-Small parameters
  • Time-frequency analysis

Download brochure    download_pdf_icon

Measurement of Harmonic Distortion Audibility Using A Simplified Psychoacoustic Model

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A perceptual method is proposed for measuring harmonic distortion audibility. This method is similar to the CLEAR (Cepstral Loudness Enhanced Algorithm for Rub & buzz) algorithm previously proposed by the authors as a means of detecting audible Rub & Buzz which is an extreme type of distortion[1,2]. Both methods are based on the Perceptual Evaluation of Audio Quality (PEAQ) standard[3]. In the present work, in order to estimate the audibility of regular harmonic distortion, additional psychoacoustic variables are added to the CLEAR algorithm. These variables are then combined using an artificial neural network approach to derive a metric that is indicative of the overall audible harmonic distortion. Experimental results on headphones are presented to justify the accuracy of the model.

Authors: Steve Temme, Pascal Brunet and Parastoo Qarabaqi
Presented at the 131th AES Convention, San Francisco, 2012

Full Paper